i'd have to agree and say that there's very little that you can do in terms of sports that requires a 50mm and simply can't be done with an 85mm. if you need the extra width, you could always save up an extra month and drop money on a 35L or something. it has a fast aperture, quick AF, and is wickedly sharp at f/2. otherwise, i think the 85mm f/1.8 is your best bet.
while i had it, my 50mm f/1.4 wasn't lightning quick to focus, but it wasn't a slouch either. at f/2 it was tack sharp, the lens was very light, and it's very affordable. what major fault do you find with the 50mm f/1.4? the only flaw that i found was it's build, and softness wide open but at f/2 it was very sharp.